错流式移动床冷渣器气固换热特性的模拟研究  

Simulation on Gas-Solid Heat Transfer Characteristics of a Bottom Ash Cooler in the Cross-flow Moving Bed

作　　者：杨宇 林顺洪[1,2] 田野 柏继松[1,2] 季炫宇[1] 徐明[1,2] 卢啸风[3] YANG Yu;LIN Shunhong;TIAN Ye;BAI Jisong;JI Xuanyu;XU Ming;LU Xiaofeng(School of Mechanical and Power Engineering,Chongqing University of Science and Technology,Chongqing 401331,China;Chongqing Waste to Energy Research&Technology Institute,Chongqing University of Science and Technology,Chongqing 401331,China;School of Energy and Power Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆科技学院机械与动力工程学院,重庆401331 [2]重庆科技学院重庆垃圾焚烧发电技术研究院,重庆401331 [3]重庆大学能源与动力工程学院,重庆400044

出　　处：《动力工程学报》2020年第3期224-230,共7页Journal of Chinese Society of Power Engineering

基　　金：重庆市教委基金资助项目(KJQN201901521);重庆市生活垃圾资源化处理协同创新中心资助项目(shljzyh2018-004)。

摘　　要：为高效回收循环流化床锅炉燃烧后排出的高温底渣余热,提出了一种错流式移动床冷渣器,并采用Fortran语言模拟其气固换热特性,分析气体入口流速、底渣下落速度和底渣粒径对底渣冷却及余热再利用的影响。结果表明:较高的气体入口流速有利于底渣的快速冷却,但会使系统能耗提高,底渣余热再利用率降低;较快的底渣下落速度延长了底渣的冷却过程,使系统能耗小幅提高,但系统处理能力也提高,而底渣余热再利用率呈先提高后降低的趋势;底渣粒径对气固换热能力的影响较小,但底渣粒径的减小会大幅提高系统能耗;在错流式移动床冷渣器内,吸热后的气体出口温度可达800℃,底渣余热再利用率约为40%,表明其具有较好的底渣冷却及余热回收能力。A bottom ash cooler was proposed for the cross-flow moving bed to recover and utilize the waste heat in the high-temperature bottom ash discharged from a circulating fluidized bed boiler,for which,a mathematical model was compiled by the Fortran language to investigate the gas-solid heat transfer characteristics,and to analyze the effects of inlet gas velocity,ash drop velocity and ash particle size on the bottom ash cooling and reusing efficiency.Results indicate that a higher inlet gas velocity is beneficial for the rapid cooling of bottom ash,but it would increase the energy consumption of the system and decrease the reuse efficiency of waste heat in bottom ash.A higher ash drop velocity extends the cooling process of bottom ash and slightly elevates the energy consumption,but the handling capacity of the system rises simultaneously,when the reuse efficiency of waste heat in bottom ash firstly increases and then decreases.The decrease of ash particle size has little effect on the gas-solid heat transfer capacity,however,it sharply increases the energy consumption.In addition,in the bottom ash cooler of cross-flow moving bed,the temperature of heated flue gas could reach 800℃,and the reuse efficiency of waste heat in bottom ash is about 40%,indicating higher performance of the cooler in bottom ash cooling and reusing.

关 键 词：冷渣器 气固换热特性 气体入口流速 底渣下落速度 底渣粒径 底渣余热再利用率 

分 类 号：TK124[动力工程及工程热物理—工程热物理]